What is the most effective method of protein precipitation? - (Oct/18/2007 )

Hi,simple question.My protein is present in the cell membrane fraction on very low level, i.e. approximately several tens of picograms (in 50 micrograms of total protein).What is the most effective (powerful) method of protein precipitation (which methods gives highest recovery, generally)? Acetone, TCA, other? After the precipitation, I would like to use the protein sample for reverse phase chromatography.

Thank you.v.

-victor.m-

QUOTE (victor.m @ Oct 19 2007, 03:28 AM)

Hi,simple question.My protein is present in the cell membrane fraction on very low level, i.e. approximately several tens of picograms (in 50 micrograms of total protein).What is the most effective (powerful) method of protein precipitation (which methods gives highest recovery, generally)? Acetone, TCA, other? After the precipitation, I would like to use the protein sample for reverse phase chromatography.

Thank you.v.

If you're not bothered by denaturing the protein, either actone or TCA seem to work pretty much the same, but remember to keep the TCA cold.If you would like native protein, try ammonium sulphate precipitation, which will also allow some partial fractionation of the protein mix.

-swanny-

i agree with swanny that ammonium sulfate is probably your best option but cold acetone will also give you a viable protein.